US20150078564A1 - Echo cancellation algorithm for long delayed echo - Google Patents

Echo cancellation algorithm for long delayed echo Download PDF

Info

Publication number
US20150078564A1
US20150078564A1 US13/995,560 US201213995560A US2015078564A1 US 20150078564 A1 US20150078564 A1 US 20150078564A1 US 201213995560 A US201213995560 A US 201213995560A US 2015078564 A1 US2015078564 A1 US 2015078564A1
Authority
US
United States
Prior art keywords
delay
correlation
signal
cross
recited
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US13/995,560
Other languages
English (en)
Inventor
Yongfang Guo
Xintian E. Lin
Ulun Karacaoglu
Narayan Biswal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Intel Corp
Original Assignee
Intel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Intel Corp filed Critical Intel Corp
Assigned to INTEL CORPORATION reassignment INTEL CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BISWAL, NARAYAN, KARACAOGLU, ULUN, LIN, XINTIAN E., GUO, YONGFANG
Publication of US20150078564A1 publication Critical patent/US20150078564A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
    • G10L21/00—Speech or voice signal processing techniques to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility
    • G10L21/02—Speech enhancement, e.g. noise reduction or echo cancellation
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
    • G10L21/00—Speech or voice signal processing techniques to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility
    • G10L21/02—Speech enhancement, e.g. noise reduction or echo cancellation
    • G10L21/0208—Noise filtering
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
    • G10L21/00—Speech or voice signal processing techniques to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility
    • G10L21/02—Speech enhancement, e.g. noise reduction or echo cancellation
    • G10L21/0208—Noise filtering
    • G10L21/0216—Noise filtering characterised by the method used for estimating noise
    • G10L21/0232—Processing in the frequency domain
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04M—TELEPHONIC COMMUNICATION
    • H04M9/00—Arrangements for interconnection not involving centralised switching
    • H04M9/08—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
    • H04M9/082—Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic using echo cancellers
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10L—SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING
    • G10L21/00—Speech or voice signal processing techniques to produce another audible or non-audible signal, e.g. visual or tactile, in order to modify its quality or its intelligibility
    • G10L21/02—Speech enhancement, e.g. noise reduction or echo cancellation
    • G10L21/0208—Noise filtering
    • G10L2021/02082—Noise filtering the noise being echo, reverberation of the speech

Definitions

  • Echo cancellers are commonly used to cancel echoes in communications circuits to minimize signal interference that may distract users and cause a reduction in quality of communication. Since an echo delay path in the communication circuits may create long delay intervals, an echo cancellation filter should be capable of modeling an impulse response characteristic equivalent to long delay intervals. In other words, the longer the delay intervals, the more complex would be the corresponding echo cancellation filter needed to cancel the echoes.
  • WiDi wireless display
  • TV television
  • WiDi wireless display
  • the WiDi technology makes the audio and video streaming more convenient and a display may be made available to a wider audience.
  • the WiDi technology may introduce an additional delay that current echo cancellation filters may not address. Accordingly, a solution for the long delayed echo, such as the long delayed echo created by the WiDi technology may be implemented in the current wireless devices to save costs.
  • FIG. 1 illustrates an example echo environment between devices.
  • FIG. 2 illustrates an example direct acoustic path echo at a near-end device.
  • FIG. 3 illustrates an exemplary direct acoustic path echo at a near-end device that includes WiDi features.
  • FIG. 4 illustrates an exemplary cross-correlation estimation that is used to estimate delay by delay estimator.
  • FIG. 5 is an example process chart illustrating an example method for loop for implementing echo cancellation algorithm for long delayed echo.
  • FIG. 6 is an example computing device to implement echo cancellation algorithm for long delayed echo.
  • a WiDi feature in a device during the wire or wireless voice communications may add an additional echo delay.
  • the WiDi feature of the device transmits an audio electrical signal from the device to a television (TV) or display device through a wireless or WiFi link.
  • the display device converts the audio electrical signal into an audio sound signal that may be reflected by surrounding environment and picked-up by a microphone of the device.
  • a long delayed echo is produced at the device due to the WiFi link path and the path travelled by the audio sound signal from the display device to the microphone of the device.
  • a delay estimator component is configured to estimate amount of the long delayed echo that includes the delay incurred from the device to the display device and from the display device to the microphone of the device.
  • the delay estimator component performs cross-correlations of a received signal (e.g., audio electrical signal) and resulting echo signal received through the microphone of the device.
  • the estimated amount of the long delayed echo is inserted to a standard echo cancellation system through a delay insertion component.
  • the delay insertion component may act as an interface to the delay estimator component for implementing the echo cancellation algorithm for the long delayed echo.
  • FIG. 1 illustrates an example echo environment 100 between devices 102 .
  • a far-end device 102 - 2 conducts a wired or wireless voice communications with a near-end device 102 - 4 .
  • the wired or wireless voice communications may include (but is not limited to) audio conference calls with WiDi, hands-free car phone systems, a standard telephone or cell-phone in hands-free mode, and the like.
  • the far-end device 102 - 2 includes a user (not shown) who is initiating and delivering an audio conversation to another user (not shown) at the near-end device 102 - 4 .
  • the audio conversation may be delivered through a wired or wireless link 104 from the far-end device 102 - 2 to the near-end device 102 - 4 .
  • a loudspeaker component (not shown) may generate an audio sound signal that bounces back (e.g., due to surrounding environment) and re-enters into a microphone component (not shown) of the near-end device 102 - 4 .
  • the re-entering audio sound signal may be referred to as a direct acoustic path echo.
  • the direct acoustic path echo may be transmitted as unwanted signal (not shown) through a wired or wireless link 106 and if not cancelled, the unwanted signal may be heard or interfere at the far-end device 102 - 2 . Due to slight round-trip transmission delay, the direct acoustic path echo may create distraction between users (not shown) of the device 102 during the wired or wireless voice communications.
  • FIG. 2 illustrates an example direct acoustic path echo 200 at the near-end device 102 - 4 .
  • an acoustic echo canceller at the near-end device 102 - 4 may use an adaptive filter component 202 to cancel echoes.
  • a signal x(n) 204 may carry an electrical audio signal that includes voice conversations from the user (not shown) at the far-end device 102 - 2 through the link 104 .
  • the electrical audio signal may be transformed into an audio sound signal 206 by a loudspeaker 208 at the near-end device 102 - 4 .
  • the audio sound signal 206 may be reflected back by the surrounding environment (e.g., wall 210 ) to a microphone 212 of the near-end device 102 - 4 .
  • the audio sound signal signals 206 - 2 and 206 - 4 are reflected through different paths by the wall 210 .
  • Other multiple paths may be traversed by the audio sound signal 206 and may find its way back to the microphone 212 . Since the audio sound signal 206 travels through the different paths (e.g., audio sound signal paths 206 - 2 and 206 - 4 ), the audio sound signal 206 may be picked-up by the microphone 212 at slightly different time.
  • a signal d(n) 214 may represent the picked-up audio sound signal signals that may be transmitted back to the far-end device 102 - 4 through the link 106 if not cancelled.
  • the signal d(n) 214 may include the unwanted signal that may be re-transmitted back and interferes with the user (not shown) at the far-end device 102 - 4 .
  • the adaptive filter component 202 may process the signal x(n) 204 using adaptive filter algorithms, such as least mean squares (LMS) algorithm, normalized LMS (NLMS) algorithm, or root mean square (RMS) algorithm to create an output y(n) 216 .
  • LMS least mean squares
  • NLMS normalized LMS
  • RMS root mean square
  • the adaptive filter component 202 may algorithmically alter its parameters in order to minimize a function of the difference between the signal d(n) 214 and its actual output y (n) 216 through a differential component 218 .
  • an error signal e(n) 220 is fed back into the adaptive filter component 202 where the filter characteristics are altered accordingly.
  • the output y(n) 216 when combined or subtracted from the d(n) 214 through the differential component 218 may result to elimination or cancellation of the unwanted signal d(n) 214 .
  • the adaptive filter component 202 may further include a self-adjusting transfer function according to an optimization algorithm that is driven by the error signal e(n) 220 .
  • the adaptive filter component 202 may use the error signal e(n) 220 to refine its transfer function to match changing parameters in the signals x(n) 204 and d(n) 214 .
  • FIG. 3 illustrates an example direct acoustic path echo 300 at the near-end device 102 - 4 that includes WiDi features.
  • a tail length (i.e., length of impulse response of transfer function) of the adaptive filter component 202 may determine how much echo (e.g., d(n) 214 ) may be cancelled.
  • a an echo canceller that uses the adaptive filter component 202 may cancel the echo that includes a delay of up to 60 msec (i.e., 10 meters distance).
  • the adaptive filter component 202 may require about 1000 taps for 16 KHz audio sampling rate.
  • the “tap” may refer to different delays experienced by the reflected audio signal 206 (of FIG. 2 ) when processed by the adaptive filter component 202 .
  • a WiDi feature such as use of WiDi 302 that streams an electrical audio signal (not shown) to a TV or display device 304 through a WiFi link 306 may introduce an additional delay.
  • the additional delay may be created by the path—WiFi link 306 . Adding the additional delay to channel multipath delay created when audio signal 308 is picked-up by the microphone 212 may total to around 250 msecs as an example.
  • the audio signal 308 is produced by a loudspeaker (not shown) at the TV or display device 304 .
  • the adaptive filter component 202 may require around 5000 taps to process the total amount of delay at the same audio sampling rate of 16 KHz.
  • the adaptive filter component 202 may create an impractical filter response output due to the number of taps (i.e., 5000 taps) that are required to process the total amount of delay.
  • the adaptive filter component 202 may become unstable in addition to becoming complex and expensive to implement.
  • a delay estimator 310 is configured to first estimate a total amount of estimated delay (i.e., delay 312 ) introduced by the WiFi link 306 and the channel multipath travelled by the audio signal 308 .
  • the signals x(n) 204 and d(n) 214 are inputs to the delay estimator 310 .
  • the delay estimator 310 may estimate the delay by performing an algorithm that searches a peak (not shown) of cross-correlations between the signals x(n) 204 and d(n) 214 .
  • the peak of the cross-correlations between the signals x(n) 204 and d(n) 214 may correspond to the estimated delay (i.e., delay 312 ).
  • the estimation performed by the delay estimator 310 may include two steps.
  • a first search includes a coarse search with a larger step size, such as at least 6.25 ms.
  • the coarse search of the step size 6.25 ms is taken from 100 samples for 16 KHz audio sampling rate.
  • the step size 6.25 ms is used as an incremental rate for searching the peak cross-correlation between the signals x(n) 204 and d(n) 214 .
  • a second search i.e., a fine search, is performed on the searched peak cross-correlation (from the first coarse search).
  • the fine search may be implemented by introducing a different and/or smaller delay of at least 62.5 ⁇ s.
  • the fine search increments the delay by 62.5 ⁇ s until a maximum cross-correlation is determined.
  • the maximum cross-correlation is the delay 312 that is fed to a delay insertion component 314 .
  • the delay insertion component 314 may act as an interface to the delay 312 prior to regular performance of echo cancellation algorithm by the adaptive filter component 202 .
  • the regular performance of the echo cancellation algorithm may exclude presence of the long tail length in the transfer function of the adaptive filter component 202 .
  • FIG. 4 illustrates an exemplary cross-correlation estimation 400 that is used to estimate delay at the delay estimator 310 .
  • Cross-correlation is a process or means of determining a degree of similarity between two signals, such as the signals x(n) 204 and d(n) 214 .
  • the signal x(n) 204 may represent a sample of the audio electrical signal from the far-end device 102 - 2 , which is delayed by an amount z ⁇ d 402 before being cross-correlated or compared with the signal d(n) 214 .
  • the z ⁇ d 402 may include the incremental time, such as the step size used on the first and second searches as discussed above.
  • a unit delay z ⁇ d 402 may include 6.25 msecs while the unit delay z ⁇ d 402 for the second search may include 62.5 ⁇ sec.
  • an output 404 may include a delayed value sample of the x(n) 204 that is cross-correlated with the signal d(n) 214 through a cross-correlation component 406 .
  • the cross-correlation component 406 may provide an output 408 that is received by an adder component 410 - 2 .
  • the adder component 410 - 2 may sum up the output 408 at each unit delay of z ⁇ d 402 until the first search and/or the second search is performed to create an output p(d) 412 .
  • the p(d) 412 may be equal to total power of the different cross-correlations between the signals x(n) 204 and d(n) 214 after the first search or the second search is performed.
  • a power of sampled signal d(n) 214 is summed up by an adder 410 - 4 to provide an output Pd 414 while a power of sampled signal x(n) 204 is summed up by an adder 410 - 6 to provide an output Px. 416 .
  • the P(d) 414 may include total power reference from the signal d(n) 214 as part of the algorithm that is implemented by the delay estimator 310 .
  • output Px 416 may include total power reference from the signal x(n) 204 as part of the algorithm that is implemented by the delay estimator 310 .
  • a power estimator 418 may estimate delay by determining ratio of the P(d) 414 to the square root of the product of the Px 416 and the Pd 414 .
  • the power estimator 418 provides a cross-correlation output (i.e., Xcorr(d) 420 ) that includes a maximum peak cross-correlations between functions of the signals x(n) 204 and d(n) 214 to determine the estimated delay (e.g., delay 312 in FIG. 3 ).
  • FIG. 5 shows an example process chart 500 illustrating an example method for implementing echo cancellation algorithm for long delayed echo.
  • the order in which the method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method, or alternate method. Additionally, individual blocks may be deleted from the method without departing from the spirit and scope of the subject matter described herein. Furthermore, the method may be implemented in any suitable hardware, software, firmware, or a combination thereof, without departing from the scope of the invention.
  • a computer accessible medium may implement the echo cancellation algorithm for the long delayed echo in the device 102 .
  • the delay estimator may receive the electrical audio signal (e.g., x(n) 204 ) and the picked-up signal (e.g., d(n) 214 ) to estimate amount of delay that includes a delay due to a WiFi link (e.g., WiFi link 306 ) and channel multipath signals (e.g., audio sound signal signal 308 ).
  • the delay estimator may receive the electrical audio signal (e.g., x(n) 204 ) and the picked-up signal (e.g., d(n) 214 ) to estimate amount of delay that includes a delay due to a WiFi link (e.g., WiFi link 306 ) and channel multipath signals (e.g., audio sound signal signal 308 ).
  • a cross-correlation is performed between the electrical audio signal and the picked up signal by the delay estimator to estimate delay.
  • the delay estimator 310 may perform cross-correlation algorithm to estimate the delay created by the WiFi link 306 and the audio sound signal 308 .
  • a first search e.g., coarse search
  • 6.25 msecs e.g., z ⁇ d 402 is 6.25 msecs
  • a second search (e.g., fine search) is performed at a step size of 62.5 ⁇ s (e.g., z ⁇ d 402 is 62.5 ⁇ s) to find the final estimate (e.g., delay 312 ) created by the WiFi link 306 and the audio sound signal 308 .
  • a delay insertion component (e.g., delay insertion 314 ) may be implemented as an interface between the delay estimator 310 and an adaptive filter component (e.g., adaptive filter component 202 ).
  • the adaptive filter component 202 may include a self-adjusting transfer function to provide an output (e.g., y(n) 216 ) that closely resembles the value of the picked-up signal d(n) 214 .
  • determining difference between the output of the adaptive filter component and the pick-up signal is performed.
  • a differential component e.g., differential component 218
  • the differential component 218 may provide an error output (e.g., e(n) 220 ) that is compared to a threshold value for performing another delay estimation. For example, if the error output e(n) 220 exceeds the threshold value (e.g., 0.01), then following YES at block 504 , another cross-correlation is performed to estimate delay by the delay estimator 310 . Otherwise, following NO at block 512 , the error output e(n) 220 is provided to far-end talker (e.g., far-end talker 102 - 2 ), which includes a completely cancelled echo signal if the error output e (n) 220 is zero value.
  • the delay estimator 210 may not have to perform the cross-correlation continuously since a near-end environment do not vary (i.e., delay profile of the environment is almost constant).
  • FIG. 6 is an example system that may be utilized to implement various described embodiments. However, it will be readily appreciated that the techniques disclosed herein may be implemented in other computing devices, systems, and environments.
  • the computing device 600 shown in FIG. 6 is one example of a computing device and is not intended to suggest any limitation as to the scope of use or functionality of the computer and network architectures.
  • computing device 600 typically includes at least one processing unit 602 and system memory 604 .
  • system memory 604 may be volatile (such as RAM), non-volatile (such as ROM, flash memory, etc.) or some combination thereof.
  • System memory 604 may include an operating system 606 , one or more program modules 608 that implement the long delay echo algorithm, and may include program data 610 .
  • a basic implementation of the computing device 600 is demarcated by a dashed line 614 .
  • the program module 608 may include a module 612 configured to implement the one-tap connection and synchronization scheme as described above.
  • the module 612 may carry out one or more of the method 500 , and variations thereof, e.g., the computing device 600 acting as described above with respect to the device 102 .
  • Computing device 600 may have additional features or functionality.
  • computing device 600 may also include additional data storage devices such as removable storage 616 and non-removable storage 618 .
  • the removable storage 616 and non-removable storage 618 are an example of computer accessible media for storing instructions that are executable by the processing unit 602 to perform the various functions described above.
  • any of the functions described with reference to the figures may be implemented using software, hardware (e.g., fixed logic circuitry) or a combination of these implementations.
  • Program code may be stored in one or more computer accessible media or other computer-readable storage devices.
  • the processes and components described herein may be implemented by a computer program product.
  • computer accessible media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data.
  • the terms “computer accessible medium” and “computer accessible media” refer to non-transitory storage devices and include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to store information for access by a computing device, e.g., computing device 600 and wireless mobile device 102 . Any of such computer accessible media may be part of the computing device 600 .
  • the removable storage 616 which is a computer accessible medium, has a set of instructions 630 stored thereon.
  • the set of instructions 630 When executed by the processing unit 602 , the set of instructions 630 cause the processing unit 602 to execute operations, tasks, functions and/or methods as described above, including method 500 and any variations thereof.
  • Computing device 600 may also include one or more input devices 620 such as keyboard, mouse, pen, voice input device, touch input device, etc.
  • Computing device 600 may additionally include one or more output devices 622 such as a display, speakers, printer, etc.
  • Computing device 600 may also include one or more communication connections 624 that allow the computing device 600 to communicate wirelessly with one or more other wireless devices, over wireless connection 628 based on near field communication (NFC), Wi-Fi, Bluetooth, radio frequency (RF), infrared, or a combination thereof.
  • NFC near field communication
  • Wi-Fi Wi-Fi
  • Bluetooth Bluetooth
  • RF radio frequency
  • infrared or a combination thereof.
  • computing device 600 is one example of a suitable device and is not intended to suggest any limitation as to the scope of use or functionality of the various embodiments described.
  • Universal Resource Identifier includes any identifier, including a GUID, serial number, or the like.
  • example is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word example is intended to present concepts and techniques in a concrete fashion.
  • techniques may refer to one or more devices, apparatuses, systems, methods, articles of manufacture, and/or computer-readable instructions as indicated by the context described herein.
  • the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise or clear from context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances.
  • the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more”, unless specified otherwise or clear from context to be directed to a singular form.
  • computer-readable media includes computer-storage media.
  • computer-readable media is non-transitory.
  • computer-storage media may include, but are not limited to, magnetic storage devices (e.g., hard disk, floppy disk, and magnetic strips), optical disks (e.g., compact disk (CD) and digital versatile disk (DVD)), smart cards, flash memory devices (e.g., thumb drive, stick, key drive, and SD cards), and volatile and non-volatile memory (e.g., random access memory (RAM), read-only memory (ROM)).
  • magnetic storage devices e.g., hard disk, floppy disk, and magnetic strips
  • optical disks e.g., compact disk (CD) and digital versatile disk (DVD)
  • smart cards e.g., compact disk (CD) and digital versatile disk (DVD)
  • smart cards e.g., compact disk (CD) and digital versatile disk (DVD)
  • flash memory devices e.g., thumb drive, stick, key drive, and SD cards
  • logic used herein includes hardware, software, firmware, circuitry, logic circuitry, integrated circuitry, other electronic components and/or a combination thereof that is suitable to perform the functions described for that logic.
  • a device comprising: a wireless display (WiDi) component adapted to transmits an electrical audio signal through a wireless link, wherein the electrical audio signal is transformed into an audio sound signal that is received by the device; a delay estimator component adapted to perform cross-correlation between the electrical audio signal and the received audio sound signal to estimate total delay, wherein the total delay includes a delay due to the wireless link and multipath delay traversed by the received audio sound signal; a delay insertion component adapted to insert the estimated total delay to an adaptive filter for echo cancellation; and an adaptive filter configured to perform echo cancellation algorithm.
  • WiDi wireless display
  • a delay estimator component adapted to perform cross-correlation between the electrical audio signal and the received audio sound signal to estimate total delay, wherein the total delay includes a delay due to the wireless link and multipath delay traversed by the received audio sound signal
  • a delay insertion component adapted to insert the estimated total delay to an adaptive filter for echo cancellation
  • an adaptive filter configured to perform echo cancellation algorithm.
  • a device wherein the electrical audio signal is received from a far-end device through a wired or wireless communication channel.
  • a device wherein the electrical audio signal is transmitted by the WiDi component to a WiDi compatible display device using the wireless link.
  • a device wherein the delay estimator component performs the cross-correlation by implementing a first coarse search to find a peak cross-correlation performs the cross-correlation by implementing a first coarse search to find a peak cross-correlation.
  • a device wherein the delay estimator component performs the cross-correlation on the peak cross-correlation due to the first coarse search, wherein the cross-correlation is implemented by a second fine search that includes a unit delay that is smaller than the unit delay that is used in the first coarse search.
  • a device wherein the delay estimator component performs the cross-correlation on the peak cross-correlation due to the first coarse search, wherein the cross correlation is implemented by a second fine search that includes a different and/or lesser number of samples than the samples used on the first coarse search.
  • a device wherein the delay insertion component acts as an interface between the delay estimator and the adaptive filter.
  • a device wherein the adaptive filter implements a transfer function that includes a short tail length implements a transfer function that includes a short tail length.
  • a device wherein the adaptive filter includes a configured threshold value to determine whether another delay estimation is performed includes a configured threshold value to determine whether another delay estimation is performed.
  • a device wherein the adaptive filter includes an output that resembles the picked-up audio sound signal.
  • a method of implementing echo cancellation algorithm for long delayed echo in a device comprising: receiving an electrical audio signal and a picked-up signal, wherein the picked-up signal includes an additional delay due to a wireless display (WiDi) feature of the device; performing cross-correlation between the electrical audio signal and the picked-up signal to estimate delay; feeding the estimated delay to an adaptive filter; determining difference between an output of the adaptive filter and the picked-up signal; and outputting an error signal that includes the difference between the output of the adaptive filter and the picked-up signal.
  • WiDi wireless display
  • a method wherein the electrical audio signal is streamed by a WiDi component through a wireless link, wherein the wireless link, includes a path for the additional delay.
  • a method wherein the cross-correlation is performed by implementing a first search to find a peak cross-correlation that includes an initial estimated delay.
  • a method wherein the cross-correlation is not continuously performed since a near-end environment do not vary.
  • a method wherein the cross-correlation is performed when the difference between the output of the adaptive filter and the picked-up signal is greater than a configured threshold value.
  • a method wherein the output of the adaptive filter is derived by using least mean squares (LMS) algorithm, normalized LMS (NLMS) algorithm, or root mean square (RMS) algorithm.
  • LMS least mean squares
  • NLMS normalized LMS
  • RMS root mean square
  • a method wherein the adaptive filter implements a transfer function that includes a short tail length is a method wherein the adaptive filter implements a transfer function that includes a short tail length.
  • a method wherein the adaptive filter includes the output that resembles the picked-up signal to satisfy a configured threshold value.
  • a method further comprising self-adjusting a transfer function by the adaptive filter according to an optimization algorithm that is driven by the error signal.
  • At least one computer accessible medium that performs a method of implementing echo cancellation algorithm for long delayed echo comprising: receiving an electrical audio signal and a picked-up signal by a device; performing cross-correlation between the electrical audio signal and the picked-up signal to estimate delay, wherein the estimated delay includes an additional delay in a wireless path that is used by a wireless display (WiDi) feature of the device; sending the estimated delay to an adaptive filter; determining an error signal that includes difference between an output of the adaptive filter and the picked-up signal; and outputting the error signal that is below a threshold value, wherein the threshold value indicates cancellation of the long delayed echo.
  • WiDi wireless display
  • a computer accessible medium wherein the electrical audio signal is streamed by the WiDi feature of the device to display device through the wireless path, wherein the display device transforms the electrical audio signal to an audio sound signal that is picked-up by the device.
  • a computer accessible medium wherein the cross-correlation is performed by implementing a first coarse search to find a peak cross-correlation that includes an initial estimated delay.
  • a computer accessible medium wherein the cross-correlation is performed on the peak cross-correlation to find final estimated delay, wherein the cross-correlation uses a second fine search that includes a unit delay that is smaller than the unit delay that is used in the first coarse search.
  • a computer accessible medium wherein the cross-correlation is performed when a threshold value is not satisfied.
  • a computer accessible medium wherein the output of the adaptive filter is derived by using least mean squares (LMS) algorithm, normalized LMS (NLMS) algorithm, or root mean square (RMS) algorithm.
  • LMS least mean squares
  • NLMS normalized LMS
  • RMS root mean square
  • a computer accessible medium wherein the adaptive filter implements a transfer function that includes a short tail length.
  • a computer accessible medium wherein the adaptive filter includes the output that resembles the picked-up signal to satisfy a configured threshold value.
  • a computer accessible medium further comprising comparing the difference in a differential component to a configured threshold value.
  • a computer accessible medium further comprising self-adjusting a transfer function by the adaptive filter according to an optimization algorithm that is driven by the error signal.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computational Linguistics (AREA)
  • Quality & Reliability (AREA)
  • Health & Medical Sciences (AREA)
  • Audiology, Speech & Language Pathology (AREA)
  • Human Computer Interaction (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Circuit For Audible Band Transducer (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
US13/995,560 2012-06-08 2012-06-08 Echo cancellation algorithm for long delayed echo Abandoned US20150078564A1 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2012/041599 WO2013184130A1 (en) 2012-06-08 2012-06-08 Echo cancellation algorithm for long delayed echo

Publications (1)

Publication Number Publication Date
US20150078564A1 true US20150078564A1 (en) 2015-03-19

Family

ID=49712385

Family Applications (1)

Application Number Title Priority Date Filing Date
US13/995,560 Abandoned US20150078564A1 (en) 2012-06-08 2012-06-08 Echo cancellation algorithm for long delayed echo

Country Status (6)

Country Link
US (1) US20150078564A1 (de)
EP (1) EP2859549A4 (de)
JP (1) JP2015521421A (de)
KR (1) KR20150002784A (de)
CN (1) CN104364844B (de)
WO (1) WO2013184130A1 (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3468162A4 (de) * 2016-05-25 2019-04-10 Tencent Technology (Shenzhen) Company Limited Verfahren und vorrichtung zur verfolgung von echoverzögerung
US10362394B2 (en) 2015-06-30 2019-07-23 Arthur Woodrow Personalized audio experience management and architecture for use in group audio communication
US20200152167A1 (en) * 2018-11-08 2020-05-14 Knowles Electronics, Llc Predictive acoustic echo cancellation
US20200169811A1 (en) * 2018-11-23 2020-05-28 Quanta Computer Inc. Environmental detection system and sound control method using the same
US11151976B2 (en) 2017-10-19 2021-10-19 Zhejiang Dahua Technology Co., Ltd. Methods and systems for operating a signal filter device
US11238879B2 (en) * 2017-11-02 2022-02-01 Microsemi Semiconductor (U.S.) Inc. Acoustic delay measurement using adaptive filter with programmable delay buffer
US20220060825A1 (en) * 2020-08-18 2022-02-24 Realtek Semiconductor Corp. Delay estimation method, echo cancellation method and signal processing device utilizing the same

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3257236B1 (de) 2015-02-09 2022-04-27 Dolby Laboratories Licensing Corporation Verbergung eines nahen sprechers, verbesserung von doppeltem dialog und automatische stummschaltung von akustisch nahen teilnehmern
CN112116919B (zh) * 2019-06-19 2024-06-04 杭州海康威视数字技术股份有限公司 一种回声消除方法、装置及电子设备
KR20220132203A (ko) * 2021-03-23 2022-09-30 삼성전자주식회사 오디오 데이터 처리 방법 및 이를 지원하는 전자 장치

Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5323459A (en) * 1992-11-10 1994-06-21 Nec Corporation Multi-channel echo canceler
US5473702A (en) * 1992-06-03 1995-12-05 Oki Electric Industry Co., Ltd. Adaptive noise canceller
US5737410A (en) * 1993-12-23 1998-04-07 Nokia Telecommunication Oy Method for determining the location of echo in an echo canceller
US5896452A (en) * 1996-05-24 1999-04-20 Motorola, Inc. Multi-channel echo canceler and method using convolution of two training signals
US6278785B1 (en) * 1999-09-21 2001-08-21 Acoustic Technologies, Inc. Echo cancelling process with improved phase control
US6421443B1 (en) * 1999-07-23 2002-07-16 Acoustic Technologies, Inc. Acoustic and electronic echo cancellation
US6687372B1 (en) * 1999-05-10 2004-02-03 Telefonaktiebolaget Lm Ericsson (Publ) Pure delay estimation
US6928160B2 (en) * 2002-08-09 2005-08-09 Acoustic Technology, Inc. Estimating bulk delay in a telephone system
US7016488B2 (en) * 2002-06-24 2006-03-21 Freescale Semiconductor, Inc. Method and apparatus for non-linear processing of an audio signal
US7251299B2 (en) * 2002-05-23 2007-07-31 Analog Devices, Inc. Time delay estimator
US20080205633A1 (en) * 2007-02-27 2008-08-28 Freescale Semiconductor, Inc. Estimating delay of an echo path in a communication system
US20090060167A1 (en) * 2007-08-31 2009-03-05 Hongyang Deng Adaptive filter for use in echo reduction
US7876892B1 (en) * 2005-12-22 2011-01-25 Mindspeed Technologies, Inc. Multiple echo cancellation using a fixed filter delay
US20110058667A1 (en) * 2009-09-09 2011-03-10 Oki Electric Industry Co., Ltd. Echo canceller having its effective filter taps adaptively controlled with echo cancellation amount monitored
US20110064213A1 (en) * 2009-09-11 2011-03-17 Freescale Semiconductor, Inc. Time Domain Adaptive Filter Bank for Network Echo Reduction or Cancellation
US20110261949A1 (en) * 2010-04-27 2011-10-27 Freescale Semiconductor, Inc. Techniques for Implementing Adaptation Control of an Echo Canceller to Facilitate Detection of In-Band Signals
US20110261948A1 (en) * 2010-04-27 2011-10-27 Freescale Semiconductor, Inc. Techniques for Updating Filter Coefficients of an Adaptive Filter
US20120164961A1 (en) * 2010-12-25 2012-06-28 Jie Gao Wireless Display Performance Enhancement
US20140133648A1 (en) * 2008-03-06 2014-05-15 Andrzej Czyzewski Method and apparatus for acoustic echo cancellation in voip terminal

Family Cites Families (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4562312A (en) * 1983-02-17 1985-12-31 At&T Bell Laboratories Subsampling delay estimator for an echo canceler
US5641927A (en) * 1995-04-18 1997-06-24 Texas Instruments Incorporated Autokeying for musical accompaniment playing apparatus
JPH098707A (ja) * 1995-06-23 1997-01-10 Matsushita Electric Ind Co Ltd 音声制御装置
US6166573A (en) * 1999-07-23 2000-12-26 Acoustic Technologies, Inc. High resolution delay line
JP2001282700A (ja) * 2000-03-30 2001-10-12 Canon Inc インタフェースカード、電子システム、及びインタフェースカードのインタフェース切り替え方法
EP1279316A2 (de) * 2000-04-27 2003-01-29 Koninklijke Philips Electronics N.V. Infrabass
GB0204057D0 (en) 2002-02-21 2002-04-10 Tecteon Plc Echo detector having correlator with preprocessing
AU2003216682A1 (en) * 2002-04-22 2003-11-03 Koninklijke Philips Electronics N.V. Signal synthesizing
JP4322207B2 (ja) * 2002-07-12 2009-08-26 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ オーディオ符号化方法
WO2004008806A1 (en) * 2002-07-16 2004-01-22 Koninklijke Philips Electronics N.V. Audio coding
US6917688B2 (en) * 2002-09-11 2005-07-12 Nanyang Technological University Adaptive noise cancelling microphone system
US6937723B2 (en) * 2002-10-25 2005-08-30 Avaya Technology Corp. Echo detection and monitoring
US7627111B2 (en) * 2002-11-25 2009-12-01 Intel Corporation Noise matching for echo cancellers
AU2002353422A1 (en) * 2002-12-09 2004-06-30 Telefonaktiebolaget Lm Ericsson (Publ) Echo cancellation device with mobile crosstalk control
CN1937854A (zh) * 2005-09-22 2007-03-28 三星电子株式会社 用于再现双声道虚拟声音的装置和方法
CN1952684A (zh) * 2005-10-20 2007-04-25 松下电器产业株式会社 利用麦克风定位声源的方法和装置
US8116472B2 (en) * 2005-10-21 2012-02-14 Panasonic Corporation Noise control device
DE102006032543A1 (de) * 2006-07-13 2008-01-17 Nokia Siemens Networks Gmbh & Co.Kg Verfahren und System zur Reduzierung des Empfangs unerwünschter Nachrichten
JP2008085628A (ja) * 2006-09-27 2008-04-10 Toshiba Corp エコーキャンセル装置、エコーキャンセルシステムおよびエコーキャンセル方法
US8325909B2 (en) * 2008-06-25 2012-12-04 Microsoft Corporation Acoustic echo suppression
EP2297728B1 (de) * 2008-07-01 2011-12-21 Nokia Corp. Vorrichtung und verfahren zum justieren von räumlichen hinweisinformationen eines mehrkanaligen audiosignals
CN101384105B (zh) * 2008-10-27 2011-11-23 华为终端有限公司 三维声音重现的方法、装置及系统
EP2533511B1 (de) * 2008-12-12 2015-04-22 Google, Inc. Verzögerungsschätzgerät
EP2221983B1 (de) * 2009-02-20 2011-08-31 Harman Becker Automotive Systems GmbH Akustische Echokompensierung
CN101504835B (zh) * 2009-03-09 2011-11-16 武汉大学 声场中空间感知信息量的度量方法及应用
CN101645273B (zh) * 2009-07-10 2012-02-01 中国科学院声学研究所 一种采样率差异估计与校正系统及其处理方法
CN101894564A (zh) * 2010-07-09 2010-11-24 中国科学院声学研究所 一种采样率差异估计与校正方法

Patent Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5473702A (en) * 1992-06-03 1995-12-05 Oki Electric Industry Co., Ltd. Adaptive noise canceller
US5323459A (en) * 1992-11-10 1994-06-21 Nec Corporation Multi-channel echo canceler
US5737410A (en) * 1993-12-23 1998-04-07 Nokia Telecommunication Oy Method for determining the location of echo in an echo canceller
US5896452A (en) * 1996-05-24 1999-04-20 Motorola, Inc. Multi-channel echo canceler and method using convolution of two training signals
US6687372B1 (en) * 1999-05-10 2004-02-03 Telefonaktiebolaget Lm Ericsson (Publ) Pure delay estimation
US6421443B1 (en) * 1999-07-23 2002-07-16 Acoustic Technologies, Inc. Acoustic and electronic echo cancellation
US6278785B1 (en) * 1999-09-21 2001-08-21 Acoustic Technologies, Inc. Echo cancelling process with improved phase control
US7251299B2 (en) * 2002-05-23 2007-07-31 Analog Devices, Inc. Time delay estimator
US7016488B2 (en) * 2002-06-24 2006-03-21 Freescale Semiconductor, Inc. Method and apparatus for non-linear processing of an audio signal
US6928160B2 (en) * 2002-08-09 2005-08-09 Acoustic Technology, Inc. Estimating bulk delay in a telephone system
US7876892B1 (en) * 2005-12-22 2011-01-25 Mindspeed Technologies, Inc. Multiple echo cancellation using a fixed filter delay
US20080205633A1 (en) * 2007-02-27 2008-08-28 Freescale Semiconductor, Inc. Estimating delay of an echo path in a communication system
US20090060167A1 (en) * 2007-08-31 2009-03-05 Hongyang Deng Adaptive filter for use in echo reduction
US20140133648A1 (en) * 2008-03-06 2014-05-15 Andrzej Czyzewski Method and apparatus for acoustic echo cancellation in voip terminal
US20110058667A1 (en) * 2009-09-09 2011-03-10 Oki Electric Industry Co., Ltd. Echo canceller having its effective filter taps adaptively controlled with echo cancellation amount monitored
US20110064213A1 (en) * 2009-09-11 2011-03-17 Freescale Semiconductor, Inc. Time Domain Adaptive Filter Bank for Network Echo Reduction or Cancellation
US20110261949A1 (en) * 2010-04-27 2011-10-27 Freescale Semiconductor, Inc. Techniques for Implementing Adaptation Control of an Echo Canceller to Facilitate Detection of In-Band Signals
US20110261948A1 (en) * 2010-04-27 2011-10-27 Freescale Semiconductor, Inc. Techniques for Updating Filter Coefficients of an Adaptive Filter
US20120164961A1 (en) * 2010-12-25 2012-06-28 Jie Gao Wireless Display Performance Enhancement

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Sakhnov et al., "Time Delay Estimation Algorithms For Echo Cancellation", Information and Communication Technologies and Services, Vol. 9, No. 1, March 2011, pp. 21-26. *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10362394B2 (en) 2015-06-30 2019-07-23 Arthur Woodrow Personalized audio experience management and architecture for use in group audio communication
EP3468162A4 (de) * 2016-05-25 2019-04-10 Tencent Technology (Shenzhen) Company Limited Verfahren und vorrichtung zur verfolgung von echoverzögerung
US10841432B2 (en) 2016-05-25 2020-11-17 Tencent Technology (Shenzhen) Company Limited Echo delay tracking method and apparatus
US11151976B2 (en) 2017-10-19 2021-10-19 Zhejiang Dahua Technology Co., Ltd. Methods and systems for operating a signal filter device
US11238879B2 (en) * 2017-11-02 2022-02-01 Microsemi Semiconductor (U.S.) Inc. Acoustic delay measurement using adaptive filter with programmable delay buffer
US20200152167A1 (en) * 2018-11-08 2020-05-14 Knowles Electronics, Llc Predictive acoustic echo cancellation
US10937409B2 (en) * 2018-11-08 2021-03-02 Knowles Electronics, Llc Predictive acoustic echo cancellation
US20200169811A1 (en) * 2018-11-23 2020-05-28 Quanta Computer Inc. Environmental detection system and sound control method using the same
US10694292B2 (en) * 2018-11-23 2020-06-23 Quanta Computer Inc. Environmental detection system and sound control method using the same
US20220060825A1 (en) * 2020-08-18 2022-02-24 Realtek Semiconductor Corp. Delay estimation method, echo cancellation method and signal processing device utilizing the same
US11490202B2 (en) * 2020-08-18 2022-11-01 Realtek Semiconductor Corp. Delay estimation method, echo cancellation method and signal processing device utilizing the same

Also Published As

Publication number Publication date
JP2015521421A (ja) 2015-07-27
EP2859549A1 (de) 2015-04-15
WO2013184130A1 (en) 2013-12-12
CN104364844B (zh) 2018-12-04
KR20150002784A (ko) 2015-01-07
EP2859549A4 (de) 2016-04-20
CN104364844A (zh) 2015-02-18

Similar Documents

Publication Publication Date Title
US20150078564A1 (en) Echo cancellation algorithm for long delayed echo
CN105577961B (zh) 增益控制器的自动调谐
US9756422B2 (en) Noise estimation in a mobile device using an external acoustic microphone signal
KR102056993B1 (ko) 에코 제거 방법, 디바이스, 및 컴퓨터 저장 매체
US10863288B2 (en) Hearing aid with assisted noise suppression
US20160171988A1 (en) Delay estimation for echo cancellation using ultrasonic markers
US9491545B2 (en) Methods and devices for reverberation suppression
US9246545B1 (en) Adaptive estimation of delay in audio systems
US9866792B2 (en) Display apparatus and echo cancellation method thereof
US20160006880A1 (en) Variable step size echo cancellation with accounting for instantaneous interference
US20150086006A1 (en) Echo suppressor using past echo path characteristics for updating
KR102194165B1 (ko) 에코 제거기
JP6038635B2 (ja) 信号処理装置および信号処理方法
KR102112018B1 (ko) 영상 회의 시스템에서의 음향 반향 제거 장치 및 방법
CN106791245B (zh) 确定滤波器系数的方法及装置
US8874175B2 (en) Converting samples of a signal at a sample rate into samples of another signal at another sample rate
CN103457646A (zh) 用于频域回波抑制滤波器的方法和装置
CN114979344A (zh) 回声消除方法、装置、设备及存储介质
CN111989934B (zh) 回声消除装置、回声消除方法、信号处理芯片及电子设备
JP5963077B2 (ja) 通話装置
EP2784778B1 (de) Akustische Echounterdrückung angesichts Sprachratenänderung
JP2015039093A (ja) エコーキャンセラおよびエコーキャンセル方法
Fukui et al. Acoustic echo canceller software for VoIP hands-free application on smartphone and tablet devices
JP2016032129A (ja) 遅延時間調整装置及び方法及びプログラム
Muzahid et al. Advanced double-talk detection algorithm based on joint signal energy and cross-correlation estimation

Legal Events

Date Code Title Description
AS Assignment

Owner name: INTEL CORPORATION, CALIFORNIA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:GUO, YONGFANG;LIN, XINTIAN E.;KARACAOGLU, ULUN;AND OTHERS;SIGNING DATES FROM 20130904 TO 20140924;REEL/FRAME:033898/0785

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION